Various techniques exist for displaying still and moving images. One such technique involves the use of passive optical projection systems, which commonly employ a projector in connection with a passive display screen. In passive systems, all of the optical energy to display an image is typically generated by the projector. This often requires use of expensive bulbs or lamps that can consume a significant amount of power and generate excessive heat. Many systems employ cooling fans to dissipate the excess heat. The cooling fans often produce undesirable noise, in addition to adding to the manufacturing expense and complexity of the projection system. In addition, passive systems commonly employ mirrors, color wheels, polarizers and other optical components between the light source and the display screen. These components can increase the expense of the system, degrade image quality, and make it difficult to maintain image quality when producing images of varying size and/or brightness.